1. Technical Field
The present invention relates to a transport device for transporting a roll-shaped recording medium having a function of positioning the roll-shaped recording medium and a recording apparatus.
2. Related Art
Hereinafter, an ink jet printer, which is an example of a recording apparatus, will be described. Among the ink jet printers, there is a large ink jet printer capable of ejecting ink onto a recording medium having a large size, such as an A1+ (extension) size or a B0+ (extension) size, to perform recording. The large ink jet printer generally uses roll-shaped recording media having a roll width of 24 inches (about 610 mm), 36 inches (about 914 mm), or 44 inches (about 1118 mm), and a roll length of 10 m to 45 m. In addition, various kinds of roll-shaped recording media have been used. For example, roll-shaped recording media made of different materials, such as paper or a film, roll-shaped recording media having high rigidity, such as resin-coated photo paper, and roll-shaped recording media having low rigidity, such as plain paper, have been used.
In the ink jet printer, a printer body is provided with a roll holder that sets a roll-shaped recording medium (hereinafter, referred to as a roll sheet). In the related art, a plurality of roll shafts having different lengths are used to correspond to the roll widths of roll sheets. The roll shaft is inserted into a roll core of the roll sheet and then the roll sheet is set to the roll holder. However, the operation of setting the roll sheet needs to ensure a large working space, or the setting operation becomes complicated. In addition, when a long roll shaft is used, the roll shaft is likely to be bent, which causes the roll sheet to be obliquely transported.
Therefore, JP-A-2007-261754 discloses a device for supporting a roll-shaped recording medium. In the device for supporting a roll-shaped recording medium, flange members, serving as roll retainers, are attached to both sides of the roll-shaped recording medium. Then, first, a driven flange member is mounted to a second holder member that is disposed on the driven side of the roll holder and can be rotated in a roll width direction. Then, the second holder member is moved together with the roll sheet to a first holder member that is disposed on the driving side of the roll holder to mount the driving flange member attached to the roll sheet to the first driving holder member, thereby setting the roll sheet to the roll holder.
According to the device for supporting a roll-shaped recording medium having the above-mentioned structure, the problems of the related art, such as a large working space, a complicated setting operation, and the oblique transport of a roll sheet due to the bending of a roll shaft, are solved.
However, when the roll sheet set to the second holder member is moved to be set to the first holder member, it is difficult to sufficiently move the roll sheet and backlash is likely to occur between the driving flange member and the first holder member. When the roll sheet is drawn while the backlash occurs, the position of the reference edge of the roll sheet is not determined, and an image is not recorded at a desired position on the roll sheet.